increase txn in ledger target to 1000 (#372)

Author: RichardAH

src/ripple/app/misc/TxQ.h

@@ -111,7 +111,7 @@ class TxQ
         std::uint32_t minimumTxnInLedgerSA = 1000;
         /// Number of transactions per ledger that fee escalation "works
         /// towards".
-        std::uint32_t targetTxnInLedger = 256;
+        std::uint32_t targetTxnInLedger = 1000;
         /** Optional maximum allowed value of transactions per ledger before
             fee escalation kicks in. By default, the maximum is an emergent
             property of network, validator, and consensus performance. This